> ## Documentation Index
> Fetch the complete documentation index at: https://docs.enfinitos.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Introduction

> EnfinitOS is the governance and operating-layer infrastructure that DOOH and spatial-media operators run for runtime, proof, metering, and settlement discipline.

EnfinitOS is the operating layer for governed screen and spatial
execution, proof, and rollout. This is the developer documentation —
the public-facing reference for every SDK, the full OpenAPI 3.1 spec,
and the open-source auditor that verifies every proof pack the
platform issues.

## The six-layer architecture

<CardGroup cols={2}>
  <Card title="Control" icon="lock">
    Define who can run what, under which rules, with which explicit
    rollout and promotion permissions.
  </Card>

  <Card title="Runtime" icon="play">
    Operate execution across screen estates through a disciplined
    runtime instead of ad hoc orchestration.
  </Card>

  <Card title="Spatial" icon="cube">
    23 substrates from DOOH to drones — first-class in the type
    system, governed by the same runtime.
  </Card>

  <Card title="Proof" icon="signature">
    Every delivery, activity, and operating action is inspectable —
    signed, chained, and verifiable offline.
  </Card>

  <Card title="Metering" icon="gauge">
    The usage and operational signals required for accountable
    commercial, operational, and customer review decisions.
  </Card>

  <Card title="Settlement" icon="scale-balanced">
    A path from verified activity into finance, invoicing, and
    settlement discipline without bolting it on later.
  </Card>
</CardGroup>

## The two pillars of trust

<CardGroup cols={2}>
  <Card title="Signed and chained" icon="shield-check">
    Every proof pack is signed by EnfinitOS with a long-lived Ed25519
    key whose public half is published. Each pack references the
    SHA-256 hash of the previous pack for the same tenant.
  </Card>

  <Card title="Open-source verifier" icon="github" href="https://github.com/EnfinitOS/sdk-auditor-ts">
    The auditor / verifier trio is open source under MIT. Fork it,
    audit it, fuzz it. No operator has to trust EnfinitOS as a
    vendor to verify what the platform issues.
  </Card>
</CardGroup>

## Where to next

<CardGroup cols={2}>
  <Card title="Quickstart" icon="rocket" href="/quickstart">
    Send your first signed event to the EnfinitOS sandbox in under
    five minutes.
  </Card>

  <Card title="API reference" icon="code" href="/api-reference">
    The full OpenAPI 3.1 reference — try every endpoint against a
    sandboxed tenant.
  </Card>

  <Card title="SDK catalogue" icon="layer-group" href="/sdks/overview">
    Twenty-eight SDKs across 23 substrates — TypeScript, Python, Go,
    Java, Ruby, Rust, Swift, Kotlin, and more.
  </Card>

  <Card title="Substrate model" icon="diagram-project" href="/concepts/substrate-model">
    Why "substrate" rather than "channel" — and how composing
    Renderer Core lets a single rights handshake govern every
    screen you ship.
  </Card>
</CardGroup>